rs80338705

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PM5PP2

The NM_000303.3(PMM2):​c.653A>G​(p.His218Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,350 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H218L) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

PMM2
NM_000303.3 missense

Scores

8
8
3

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.74

Publications

5 publications found
Variant links:
Genes affected
PMM2 (HGNC:9115): (phosphomannomutase 2) The protein encoded by this gene catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate, which is a precursor to GDP-mannose necessary for the synthesis of dolichol-P-oligosaccharides. Mutations in this gene have been shown to cause defects in glycoprotein biosynthesis, which manifests as carbohydrate-deficient glycoprotein syndrome type I. [provided by RefSeq, Jul 2008]
PMM2 Gene-Disease associations (from GenCC):
  • congenital disorder of glycosylation type I
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
  • PMM2-congenital disorder of glycosylation
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet, PanelApp Australia, ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 uncertain in NM_000303.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-8847736-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 92805.Status of the report is criteria_provided_single_submitter, 1 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 89 curated pathogenic missense variants (we use a threshold of 10). The gene has 24 curated benign missense variants. Gene score misZ: -1.3872 (below the threshold of 3.09). Trascript score misZ: -1.8083 (below the threshold of 3.09). GenCC associations: The gene is linked to PMM2-congenital disorder of glycosylation, congenital disorder of glycosylation type I.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PMM2NM_000303.3 linkc.653A>G p.His218Arg missense_variant Exon 8 of 8 ENST00000268261.9 NP_000294.1 O15305-1A0A0S2Z4J6Q59F02
PMM2XM_047434215.1 linkc.404A>G p.His135Arg missense_variant Exon 6 of 6 XP_047290171.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PMM2ENST00000268261.9 linkc.653A>G p.His218Arg missense_variant Exon 8 of 8 1 NM_000303.3 ENSP00000268261.4 O15305-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251246
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461350
Hom.:
0
Cov.:
30
AF XY:
0.00000825
AC XY:
6
AN XY:
727016
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53336
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000135
AC:
15
AN:
1111592
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.431
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Apr 29, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: PMM2 c.653A>G (p.His218Arg) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251246 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.653A>G in individuals affected with Congenital Disorder Of Glycosylation Type 1a and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.39
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.24
CADD
Uncertain
24
DANN
Uncertain
0.98
DEOGEN2
Pathogenic
0.87
D;D;.
Eigen
Benign
0.17
Eigen_PC
Uncertain
0.29
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.91
D;D;D
M_CAP
Pathogenic
0.29
D
MetaRNN
Uncertain
0.69
D;D;D
MetaSVM
Pathogenic
0.89
D
MutationAssessor
Uncertain
2.5
.;M;.
PhyloP100
7.7
PrimateAI
Benign
0.47
T
PROVEAN
Pathogenic
-5.3
D;D;D
REVEL
Pathogenic
0.77
Sift
Uncertain
0.0010
D;D;D
Sift4G
Uncertain
0.0050
D;D;D
Polyphen
0.014
.;B;.
Vest4
0.52
MutPred
0.80
.;Loss of sheet (P = 0.1158);.;
MVP
0.93
MPC
0.0076
ClinPred
0.96
D
GERP RS
5.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.94
gMVP
0.84
Mutation Taster
=10/90
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs80338705; hg19: chr16-8941594; API